Structural Dynamics and Acoustics

Structural Dynamics and Acoustics

GCAS’s experience spans many years of aerospace product development in structural dynamics and acoustic analysis, testing and noise control. Specific project experience includes:

  • Prediction of the interior noise of aircraft due to wing mounted propeller excitation
  • Jet exhaust noise prediction using numerical methods from turbulence models as well as semi empirical methods based on test data
  • Jet exhaust noise measurements including noise source surveys of plume and correlation with turbulence measurements
  • Jet exhaust nozzle and suppressor design from predictions and substantiation of levels from measurements
  • Propeller, fan, compressor and turbine noise predictions from the unsteady aerodynamic field established on the airfoil by upstream wakes, turbulent inflow, or the shock field generated at supersonic speeds
  • Acoustic testing of fans, propellers, compressors and turbines for sound level correlation with the unsteady flow field
  • Semi empirical prediction models of combustion noise from experiments
  • The sound field generated within the combustor during liquid rocket combustion instability
  • Noise path discrimination and identification
  • Noise generated in turbulent boundary layers and wakes, including the effect of surface roughness on self noise
  • Structural borne noise, such as from vibration generated by engines, pumps and equipment through the structure to cavities and panels
  • Prediction of low level noise from motors, pumps, electrical equipment, and hydraulic systems
  • Impact noise prediction and measurement
  • Acoustic treatment design and testing
  • Flow noise in pipes and ducts
  • Prediction methods for the flow induced noise over submarines
  • Effectiveness of submarine hull coating on echo reduction
  • Acoustic fluid structure interaction for predicting the interior noise in aircraft fuselages, automobile interiors and submarine hulls
  • Noise radiation pattern prediction and measurement from structural surfaces
  • Acoustic reverberation room and anechoic chamber design and check out
  • Accuracy and precision of acoustic measurements
  • Reverberation room measurements of satellite panels, electronic packages and other sensitive equipment
  • Correlation of reverberation room environment to actual flight environment
  • General noise surveys of communities, factories, airports, etc. to meet FAA, OSHA and other governmental noise regulations
  • Design of control rooms, computer rooms, work areas, etc., for low noise
  • Correlation and coherence analysis of acoustic and other time series analysis
  • Acoustic fatigue analysis of structures including the effect of the dynamics of the structure, such as with panels
  • Sound propagation effects, including air attenuation and density gradients
  • Effect of surface reflections on measured sound levels
  • Sound enclosure design
  • Design of specialized noise measurement equipment, such as probe stems, directional arrays and mirrors

The following describes some of the contracts we have had in Structural Dynamics and Acoustics: In the area of dynamic testing GCAS has three retail test systems products: